Multiple zone well completion with separate inlet tubings and a common production tubing



June 20, 1967 c. J. COBERLY 3,326,290

MULTIPLE ZONE WELL COMPLETION WITH SEPARATE INLET TUBINGS AND A COMMON PRODUCTlON TUBING Filed Feb. 1, 1965 7 Sheets-Sheet 1 INVENTOR. 2 5g Q/qRE/VC'E GI. besaaw y Ms firm/away:-

June 20, 1967 c. J. COBERLY 3,326,290

MULTIPLE ZONE WELL COMPLETION WITH SEPARATE INLET TUBINGS AND A COMMON PRODUCTION TUBING Filed Feb. 1, 1965 '7 Sheets-Shasta INVENTOR. Llama/c5 CI. 60559:.

June 20, 1967 c. .1. COBERLY 3,326,290

MULTIPLE ZONE WELL COMPLETION WITH SEPARATE INLET TUBINGS AND A COMMON PRODUCTION TUBING 7 Sheets-Sheet 3 Filed Feb. 1, 1965 7 INVENTOR. fla s/was (2/. Z 055/91. K.

BY M's firzwwsy'r jfi /e/s, ,IJ/ECM, Jgussmm f-KEQM June 20, 1967 I Q ERLY 3,326,290

MULTIPLE ZONE WELL COMPLETION WITH SEPARATE INLET TUBINGS AND A COMMON PRODUCTION TUBING Filed Feb. 1, 1965 7 Sheets-Sheet 4 1 4a 3 25g 70 INVENTOR.

flaps/was cl 6055a June 20, 1967 c. J. COBERLY 3,326,290

MULTIPLE ZONE WELL COMPLETION WITH SEPARATE INLET TUBINGS AND A COMMON PRODUCTION TUBING Filed Feb. 1, 1965 7 Sheets-Sheet 5 INVENTOR. [Zane/v65 ('1. 608225.

BY /-//s QrraPA/Eys- 0 6 9 f 2 w 6 h 2 A WT .w 3 m e N e I h S June 20, 1967' c. J. COBERLY MULTIPLE ZONE WELL COMPLETION WIT TUBINGS AND A COMMON PRODUCTION TUBING Filed Feb. 1', 1965 [Zeke/V65 (I 60652144 INVENTOR.

- BY Ms firmweyc ,l-Iawre; 1550/, #055541. fi s/QM June 20, 1967 c. J. COBERLY. 3,326,290

MULTIPLE ZONE WELL COMPLETION WITH SEPARATE INLET TUBINC'S AND A COMMON PRODUCTION TUBING Filed Feb. 1, 1965 7 Sheets-$heet 7 1 50 Pam 4% 2. HREA/CE El. 659501.54

I NVENTOR.

BY Ms 4rmkmsyr United States Patent California Filed Feb. 1, 1965, Ser. No. 429,573 Claims. (Cl. 166-68) The present invention relates in general to oil well completions, and has as its basic object the provision of a multiple zone completion utilizing a tubing system which includes separate inlet tubings in communication with the respective zones above their lower ends and connected at their lower ends to a common production tubing for all of the zones, the inlet and production tubings preferably being in parallel, i.e., side-by-side, relation.

Another basic object of the invention is to provide a well completion of the foregoing nature wherein the tubing system is capable of achieving extremely effective separation of the oil and gas produced by each zone during production of oil from such zone by pumping, the gas produced by each zone flowing upwardly to the surface through the corresponding inlet tubing, and the oil produced by each zone being pumped upwardly to the surface through the common production tubing.

An important object is to produce the various zones one at a time without any significant intermingling of either the oil or the gas from the different zones.

Another important object of the invention is to provide an oil Well completion of the foregoing general nature which is capable of producing oil and gas from different zones efliciently and at adequate rates, even in small holes, using pumps of various types, such as a rod operated pump, a fixed fluid operated pump, a free fluid operated pump, a submersible electric pump, and the like. The tubing system of the invention may also be utilized in some instances to produce the different zones in other ways, as by flowing the various zones simultaneously or sequentially with or without gas lifting. Further, the tubing system of the invention may be utilized to produce some of the zones by pumping and to produce the remaining zones in other ways, as by flowing with or without gas lifting. However, since the invention is intended primarily for production by sequential pumping of the various zones because it is capable of achieving efficient separation of the oil and gas produced by each zone, the present disclosure will be directed primarily to producing each zone by pumping, and particularly pumping with a free fluid operated pump.

Considering the manner in which the foregoing principal objectives may be achieved, the invention preferably, but not necessarily, utilizes a casingless completion wherein the tubings of the tubing system are cemented in place in an open bore or hole, as disclosed in my Patent No. 2,939,533, granted June 7, 1960. As more fully discussed in that patent, such a completion has various basic advantages, among these being a smaller well bore for a tubing system involving a given number of tubings of given sizes, accompanying reductions in drilling costs, the elimination of the cost of a casing (except for a surface casing where required to protect underground fresh water supplies, or the like), superior support for the surrounding formations as the result of cementing the tubing system in place, and the like. However, the tubing system of the invention may also be used with packers separating the various zones.

The invention further contemplates, and an important object thereof is to provide, an oil well completion, and preferably a casingless, cemented-in-place completion of the foregoing nature, wherein each inlet tubing and the 3,325,299 Patented June 20, 1967 common production tubing cooperates to form, in effect, a U-tube, and wherein fluid from the corresponding producing zone is admitted into such inlet tubing at a level above the lower end thereof. Preferably, communication between each producing zone and the corresponding inlet tubing is achieved by perforating such inlet tubing, and the cement surrounding it, after the tubing system has been cemented in place in the well, utilizing any suitable perforating equipment. With this procedure, it is necessary to drill the well at least into the lowermost producing zone a suflicient distance to locate the lower end of the corresponding U-tube below the level at which the corresponding inlet tubing is to be perforated. Normally, unless the lowermost producing formation is eX- tremely thick, the well must be drilled to a level sufficiently below such formation to achieve eflicient oil and gas separation in the manner discussed hereinafter.

More particularly, an imporant object of the invention is to interconnect the lower end of the inlet and production tubings in fluid communication at a level considerably below that at which the lower most producing formation communicates with the corresponding inlet tubing, and to pump oil from the various zones upwardly to the surface through the production tubing, preferably by means of a pump located within the production tubing adjacent the lower end thereof. With this construction, as each zone is pumped, the oil from such zone must flow downwardly through the corresponding inlet tubing to the inlet of the pump. At the same time, gas produced by the zone in question flows upwardly through the corresponding inlet tubing from the level of the perforations therein and is drawn off at the surface. Thus, the liquid and gaseous components of the well fluid entering the inlet tubing in communication with the zone being produced flow in opposite directions in such inlet tubing, the gaseous components flowing upwardly to the surface and the liquid components flowing downwardly to the lower end of such inlet tubing and thence to the inlet of the pump in the production tubing. By locating the lower ends of the various U-tubes formed by the various inlet tubings and the production tubing an adequate distance, e.g., 50 to feet, or more, below the perforations through which fluid from the lowermost zone enters the corresponding inlet tubing, excellent gas-oil separation is obtained, enabling the pump to operate at maximum volumetric efliciency, which is an important feature. For a more complete disclosure of this gas-oil separating technique, attention is directed to co-pending application Ser. No. 213,434, filed July 30, 1962, by Val Kogut and me, now Patent No. 3,172,469, granted Mar. 9, 1965.

An essential object of the invention is to provide selector means for selectively placing the various inlet tubings in fluid communication with the production tubing, and thus with the inlet of the pump in the production tubing, at a level sufficiently below the level of the perforations in the inlet tubing in communication with the lowermost zone to achieve effective oil-gas separation with respect to the fluid produced by such zone. With this construction, oil may be pumped from the various zones one at a time without intermingling, which is an important feature. Such selector means is preferably hydraulically operated, but it may be operated electrically, by gas pressure, or otherwise.

Another essential object is to provide separate oilhandling and gas-handling facilities at the surface for the oil and gas produced by the various zones, and to provide selector means for directing the oil and gas from the different zones to the corresponding oil-handling and gas-handling facilities. With this construction, there is no intermingling of oil from the different zones, nor is there any intermingling of gas from the different zones, which is an important feature.

A further object is to provide an installation wherein the selector means for selectively placing the inlet tubings in fluid communication with the pump and the selector means for directing the oil and the gas from the different zones to the corresponding oil-handling and gas-handling facilities, are operated in timed relation so that the oil and gas from each zone are routed to the proper oilhandling and gas-handling facilities.

An important object of the invention is to provide a selector means for selectively placing the inlet tubings in fluid communication with the production tubing, and thus in fluid communication with the inlet of the pump, which includes valve means in the tubing system adjacent the lower end thereof and controllable from the surface. More particularly, an object in this connection is to provide selector valves in the respective inlet tubings for respectively connecting such inlet tubings in fluid communication with the production tubing, and to provide a control valve in the tubing system and operable from the surface for selectively operating the selector valves. A related object is to provide selector valves which incorporate check valves for preventing fluid flow from an inlet tubing contaning fluid at a relatively high pressure to an inlet tubing containing fluid at a relatively low pressure, thereby insuring against flow from a high pressure producing'zone to a low pressure producing zone.

Yet another important object of the invention is to provide a multiple zone well completion of the foregoing nature wherein the pump is a fluid operated pump adapted to be hydraulically circulated through the production tubing between the surface and an operating position in the well adjacent the lower end of the production tubing. A related object is to provide adjacent the lower end of the production tubing a standing valve valve assembly which communicates with the outlets of the various selector valves, and on Which the inlet of the fluid operated pump is seated when it is in its operating position. Another related object is to provide a supply tubing in the well for conveying operating fluid under pressure, for actuating the fluid operated pump, downwardly from the surface to the fluid operated pump. Such supply tubing may be a parallel tubing cemented in place along with the inlet and production tubings, or it may be an inner tubing disposed within one of the inlet tubings. Still another related object is to provide a closed system incorporating a return tubing for returning to the surface spent operating fluid discharged by the pump. Such return tubing may be a cemented-in-place parallel tubing, or it may be an inner tubing within one of the inlet tubings.

An important object of the invention is to provide a well completion of the foregoing nature wherein the control valve for selectively operating the various selector valves for the different zones is responsive to fluid pressure variations in the supply tubing for the fluid opera-ted pump. More particularly, an object in this connection is to provide a control valve which closes one selector valve and opens another each timethe fluid pressure in the supply tubing is reduced from the normal operating pressure to the static pressure due to the head of fluid in the supply tubing. To do this, the operating pressure at the well head must be reduced to the return tubing pressure, or approximately zero.

Still another object of the invention is to provide such a control valve which operates the various selector valves in sequence so that the different zones can be produced sequentially. A related object is to provide programming means, preferably at the surface, for varying the pressure in the supply tubing between the operating pressure and the static pressure due to the head of fluid therein according to a predetermined program so as to produce the various zones sequentially according to such program. The exact production program will be determined by various factors, such as the relative productive capacities of the different zones, the relative demands for oil and gas from the different zones, production quotas (if any) for the various zones, and the like. The programming means preferably comprises timing means, although it may include means responsive to the liquid levels in the inlet tubings, or the like.

Another object of the invention is to provide a bottomhole control valve, for sequentially operating the selector valves corresponding to the various zones, which is adapted to be hydraulically circulated through the supply tubing between the surface and an operating position adjacent the lower end of the supply tubing.

Yet another object is to provide selector valves which can be run in and out of the corresponding inlet tubings on wire lines, the same being true of the control valve if desired.

The foregoing objects, advantages, features and results of the present invention, together with various other objects, advantages, features and results thereof which will be evident to those skilled in the multiple-zone oil well producing art in the light of this disclosure, may be achieved with the exemplary embodiments of the invention described in detail hereinafter and illustrated in the accompanying drawings, in which:

FIG. 1 is a semidiagrammatic view showing the upper end of a two-zone well completion which embodies the invention, using a free fluid operated pump, and showing surface oil-handling and gas-handling facilities associated with such completion;

FIG. 2 is an enlarged downward continuation of FIG. 1, showing down hole and bottom hole portions of the two-Zone well completion of FIG. 1;

FIG. 3 is an enlarged vertical sectional view duplicating approximately the upper one-third of FIG. 2 on a larger scale, FIG. 3 being taken as indicated by the irregular arrowed line 33 of FIG. 6;

FIG. 4 is a downward continuation of FIG. 3;

FIG. 5 is a downward continuation of FIG. 4;

FIGS. 6 and 7 are horizontal sectional views respectively taken along the arrowed lines 66 and 7-7 of FIGS. 3 and 4, respectively; 7

FIG. 8 is a view similar to FIG. 6, but showing a four-zone well completion of the invention, perforations into the respective producing zones having been omitted for convenience;

FIG. 9 is a vertical sectional view of a control valve forming part of a zone selector means of the invention;

FIG. 10 is a fragmentary view duplicating a portion of FIG. 9, some parts of which are shown in vertical section in FIG. 9 being shown in elevation in FIG. 10;

FIG. 11 is a vertical sectional view of a selector valve also forming part of the zone selector means of the invention; and

FIG. 12 is a vertical sectional view of a selector valve forming part of a selector means for directing oil and gas from different producing zones to corresponding oilhandling and gas-handling facilities.

General description Referring initially to FIGS, 1 and 2 of the drawings, these figures illustrate, in a semidiagrammatic manner, a casingless, cemented-in-place, two-zone, U-tube oil well completion 20 which embodies the invention.

More particularly, the well completion 20 includes a bore or hole 22 drilled from the surface 24 downwardly through upper and lower producing formations 26 and 28 and bottomed a substantial distance, e.g., 50 to feet, or more, below the lower producing formation. Except for a surface casing 30 which may be required in some areas to prevent contamination of subsurface fresh water supplies, or the like, the well bore 22 is uncased in accordance with the practice of the aforementioned Patent No. 2,939,533.

Suspended in the uncased well bore 22 from a well head 32, shown as mounted on the surface casing 30,

is a tubing system designated generally by the numeral 34. In the particular two-zone well completion 20 shown, the tubing system 34 includes an upper-zone inlet tubing 36 in fluid communication with the upper producing formation 26, a lower-zone inlet tubing 38 in fluid communication with the lower producing formation 28, and a production tubing 40. The tubings 36, 38 and 40 are positioned in the well bore 22 in parallel or side-by-side relation and are interconnected at their lower ends, at a level 50 to 100 feet, or more, below the lower producing formation 28, in such a manner that the production tubing 40 cooperates with the upper-zone and lower-zone inlet tubings 36 and 38 to form upper-zone and lowerzone U-tubes 42 and 44 each similar to the U-tube of the aforementioned Patent No. 3,172,469.

Although, as hereinbefore outlined, the well completion 20 may be produced in other ways, it is particularly applicable to selective production of the upper and lower producing formations 26 and 28 by pumping oil from one formation or the other upwardly through the production tubing 40, and by simultaneously producing gas from the formation being pumped at any instant upwardly through the corresponding inlet tubing 36 or 38. When the upper zone 26 is being produced, the corresponding U-tube 42 acts to separate the oil and gas from such zone in the manner disclosed in Patent No. 3,172,469. The same is true of the U-tube 44 when the lower zone 28 is being produced.

The well completion 20 illustrated is particularly suitable for use with a fluid operated pump 46 capable of being circulated through the production tubing 40 hydraulically between the surface 24 and an operating position adjacent the lower end of the production tubing. When the pump 46 is in its operating position, its lower, inlet end 48 is seated on a standing valve assembly 50 carried by the tubing system 34 adjacent the lower end of the production tubing 40. As will be described in more detail hereinafter, the lower end of the standing valve assembly 50 is adapted to be connected in fluid communication with the lower end of one or the other of the inlet tubings 36 and 38, whereby the standing valve assembly delivers oil from the corresponding producing formation 26 or 28 to the inlet of the pump 46.

When the fluid operated pump 46 is in its operating position, it receives operating fluid, such as clean crude oil, under high pressure through a supply tubing 52. The spent operating fluid discharged by the pump 46 may be mixed with the production fluid in an open system and pumped upwardly to the surface through the production tubing 40. However, a closed system for the operating fluid is preferable, the tubing system 34 being shown as including a return tubing 54 for returning the spent operating fluid to the surface 24 separately from the production fluid from the particular formation 26 or 28 being produced. The supply and return tubings 52 and 54 may be disposed within the inlet tubings 36 and 38 as shown in Patent No. 3,172,469. Alternatively, as shown in the drawings, they may be positioned in the well bore 22 in parallel or side-by-side relation with the tubings 36, 38 and 40.

The entire tubing system 34 is cemented in place in the uncased well bore 22 by a body of cement 56 which surrounds all of the tubings 36, 38, 40, 52 and 54, and which cements off the producing formations 26 and 28. Preferably, the body of cement 56 extends from the bottom of the well bore 22 upwardly at least to a level above the upper producing formation 26. However, it may extend upwardly in the well bore 22 all the way to the surface 24, or at least into the lower end of the surface casing 30, if used. The level to which the body of cement 56 extends upwardly above the upper producing formation 26 depends on the nature of the formation thereabove and the extents to which they require support.

The tubing system 34 may be cemented in place in the well bore 22 by pumping cement downwardly through the inlet tubings 36 and 38, such cement being discharged through ports 58 and 60. After the necessary or desired quantity of cement has been introduced into the well bore 22 in this manner, the inlet tubings 36 and 38 are purged of cement, The necessary equipment and procedure for cementing the tubing system 34 in place to the desired level are more fully disclosed in the aforementioned Patents Nos. 2,939,533 and 3,172,469. Consequently, a further description herein is not necessary.

After the tubing system 34 has been cemented in place, the upper-zone and lower-zone inlet tubings 36 and 38, and the surrounding cement 56, are provided with perforations 62 and 64, repsectively, opposite the upper and lower producing formations 26 and 28, respectively, to establish fluid communication between the respective producing zones and inlet tubings. This may be accomplished utilizing conventional perforating equipment capable of being oriented properly to avoid perforating adjacent tubings. Perforating apparatuses of this nature, and the techniques for using them, are well known so that no additional description is required.

Alternative Well completion 70 Turning for the moment to FIG. 8 of the drawings, illustrated in horizontal section therein is an alternative well completion 70 which differs from the well completion 20 in being a four-zone completion, instead of a twozone one. More particularly, the well completion 70 includes four inlet tubings 72, 74, 76 and 78 respectively cooperating with a common production tubing 80 to form four U-tubes 82, 84, 86 and 88 each corresponding to the U-tube of the aforementioned Patent No, 3,172,469. The inlet tubings 72, 74, 76 and 78 respectively communicate with different producing formations or zones, not shown, the bottoms of the four U-tubes 82, 84, 86 and 88 being below the lowermost zone a distance of the order hereinbefore indicated.

The inlet tubings 72, 74, 76 and 78 and the production tubing 80 form parts of .a tubing system 90 which includes supply and return tubings 92 and 94 for a fluid operated pump, not shown. Such pump may be circulated through the production tubing 80 between the surface of the ground and an operating position adjacent the lower end of the production tubing in the manner to be described hereinafter in connection with the fluid operated pump 46.

The entire tubing system 90 is cemented in place in a well bore or hole 96 by a body of cement 98 in the same manner as the tubing system 34.

It will be understood that although two-zone and fourzone well completions 20 and 70 have been disclosed herein, well completions for other numbers of zones come within the invention.

Bottom-hole zone selector means 100 Within the tubing system 34 adjacent the lower end thereof is a zone selector means 100, FIG. 2, for selectively connecting the upper and lower producing formations 26 and 28 to the inlet end of the standing valve assembly 50, and thus to the inlet end 48 of the fluid operated pump 46.

More particularly, the zone selector means 100 includes a control valve 102 capable of sequentially operating upper-zone and lower-zone selector valves 104 and 106. Preferably, the control valve 102 and the selector valves 104 and 106 are fluid operated, in a manner to be described hereinafter, but they may be otherwise operated, e.g.,. electrically, or the like.

The control valve 102 is preferably hydraulically movable through the supply tubing 52 between the surface 24 and an operating position adjacent the lower end of the supply tubing. Alternatively, the control valve 102 may be installed and removed through the supply tubing 52 on a wire line.

The upper-zone and lower-zone selector valves 104 1nd 106 are movable through the respective upper-zone and lower-zone inlet tubings 36 and 38 between the surface 24 and operating positions adjacent the lower ends of the respective inlet tubings. Preferably, the selector valves 104 and 106 are installed and removed with wire lines.

When the control valve 102 actuates the upper-zone selector valve 104, the latter places the upper-zone inlet tubing 36 in communication With the inlet end of the standing valve assembly 50 through a passage 108 in the tubing system 34. Similarly, when the control valve 102 actuates the lower-zone selector valve 106, the lat ter places the lower-zone inlet tubing 38 in communication with the inlet end of the standing valve assembly 50 through a passage 110. If the inlet tubings 36 and 38 are at different pressures, the selector valves 104 and 106 are prevent flow from the inlet tubing at the higher pressure to the one at the lower pressure.

The manner in which the control valve 102 is actuated, and the manner in which the selector valves 104 and 106 perform the aforementioned functions, will be discussed in more detail hereinafter under appropriate headings.

Surface zone selector means 120 Referring to FIG 1 of the drawings, the well completion 20 includes at the surface 24 a zone selector means 120 for directing oil produced by the upper and lower zones 26 and 28 to upper-zone and lower-zone oil handling facilities or equipment 122 and 124, respectively, and for directing gas produced by the upper and lower zones 26 and 28 to upper-zone and lower-zone gas handling facilities or equipment 126 and 128, respectively.

More particularly, the zone selector means 120 includes a control valve 130 which may be identical to the control valve 102 and which is operated in timed relation therewith, as will be described hereinafter. The control valve 130 sequentially actuates (in phase with the upper-zone and lower-zone selector valves 104 and 106) upper-zone and lower-zone oil select-or valves 132 and 134 controlling distribution to the respective upperzone and lower-zone oil handling facilities 122 and 124. Similarly, the control valve 130 sequentially actuates (in phase with the upper-zone and lower-zone selector valves 104 and 106) upper-zone and lower-zone gas selector valves 136 and 138 for directing gas from the respective upper and lower producing formations 26 and 28 to the upper-zone and lower-zone gas handling facilities 126 and 128, respectively. As will be discussed hereinafter, the two control valves 102 and 130 are actuated in timed relation by a programming means 140 shown as controlling the flow of operating fluid through a supply line 142 connected to the upper end of the supply tubing 52. (A corresponding return line 144 is connected to the upper end of the return tubing 54.)

The upper-zone and lower-zone oil selector valves 132 and 134 are respectively located in branch oil production lines 146 and 148 which are connected to a common oil production line 150' in communication with the upper end of the common production tubing 40. The branch oil production lines 146 and 148 respectively lead to the upper-zone and lower-zone oil handling facilities 122 and 124 and may have inserted therein flowmeters 152 and 154 for measuring the oil production from the respective upper and lower zones 26 and 28.

The upper-zone and lower-zone gas selector valves 136 and 138 are respectively located in gas production lines 156 and 158 connecting the upper ends of the upper-zone and lower zone inlet tubings 36 and 38 to the respective upper-zone and lower-zone gas handling facilities 126 and 128.

The manner in which the control valve 130 actuates the various selector valves 132, 134, 136 and 138 will be discussed in more detail hereinafter.

Running pump 46, control valve 102, and selector valves 104 and 106 in and out Interconnecting the production, supply and return tubings 40, 52 and 54 and the production, supply and return lines 150, 142 and 144 is a control valve means 160 for connecting the lines 150, 142 and 144 to the tubings 40, 52 and 54 in various combinations depending upon whether the fluid operated pump 46 and the control valve 102 are in operation in their operating positions, or are being run in or out. When the fluid operated pump 46 and the control valve 102 are in their operating positions and in operation, the control valve means 160 connects the production, supply and return lines 150, 142 and 144 to the production, supply and return tubings 40, 52 and 54, respectively.

In order to run the fluid operated pump 46 in, it is first inserted into the upper end of the production tubing 40. The control valve means 160 is then set in a position to deliver operating fluid from the supply line 142 to the production tubing 40 above the pump 46 to displace the pump downwardly through the production tubing 40. At the same time, the control valve means 160 is set to close the upper end of the supply tubing 52, and to connect the return tubing 54 to the return line 144. As a result, fluid beneath the pump 46 is displaced upwardly through the return tubing 54 by way of a passage 162 connecting the lower end of the return tubing 54 to the lower end of the production tubing 40 adjacent the upper end of the standing valve assembly 50, as shown in FIG. 2 of the drawings. (Such displaced fluid can also enter the return tubing 54 through a passage 168 until such time as the pump 46 covers such passage.) Since the supply tubing 52 is closed with this procedure, no possibly dirty fluid in the production tubing 40 can enter the supply ttibing 52 to contaminate any clean operating fluid therein.

In running the control valve 102 in hydraulically, it is first inserted into the upper end of the supply tubing 52. The control valve means 160 is then set to connect the supply line 142 to the supply tubing 52 to displace the control valve 102 downwardly through the supply tubing 52. If the pump 46 is in its operating position, fluid beneath the control valve 102 is displaced through the return tubing 54 by way of a passage 164, FIG. 2, the control valve means 160 being set to connect the re-. turn tubing 54 to the return line 144 and to close the upper end of the production tubing 40. If the pump 46 is not in place, fluid from beneath the control valve 102 may be displaced upwardly through either or both the production and return tubings 40 and 54.

When both the fluid operated pump 46 and the fluid operated control valve 102 are in their operating positions, as shown in FIG. 2 of the drawings, and are in operation, the control valve is exposed directly to the pressure in the supply tubing 52, as will be discussed in more detail hereinafter. The fluid operated pump 46 receives the operating fluid under pressure required for its actuation by way of a passage 166, FIG. 2. The spent operating fluid discharged by the pump 46 is conveyed to the return tubing 54 by way of the passage 168. Irrespective of which of the zones 26 and 28 is being produced, the production fluid discharged by the pump 46 bypasses the pump by way of a passage 170 and flows upwardly through the production tubing 40 to the surface. (It will be noted that when the pump 46 is in its operating position, the packers on the usual packer mandrel 172 at the upper end of the pump are positioned in enlarged portions 174 of the production tubing 40 so that the upwardly-flowing production fluid can bypass the packers.)

In order to run the pump 46 out, the control valve means 160 is set to connect the supply line 142 to the return tubing 54, the upper end of the supply tubing 52 being closed and the upper end of the production tubing 40 being connected either to the return line 144, or the production line 150. Under such conditions, the operating fluid under pressure from the supply line 142 flows downwardly through the return tubing 54 and the passage 162 to unseat the pump 46 and move it upwardly in the production tubing 40. Initial upwardly movement of the pump 46 results from engagement of the usual external seals on the body of the pump with the peripheral walls of the chamber in which the pump is disposed when in its operating position. This initial upward movement is sufficient to move the packers on the packer mandrel 172 upwardly out of the enlarged portions of the production tubing 40 so that they can engage the wall of such tubing. Thereafter, the operating fluid introduced below the pump 46 acts on the packers on the packer mandrel 172 to circulate the pump to the surface 24 in the usual manner for this type of installation.

To run the control valve 102 out, the control valve means 160 is again set to connect the supply line 142 to the return tubing 54, the upper end of the production tubing 40 being closed and the supply tubing 52 being connected to the return line 144, for example. Under such conditions, the operating fluid under pressure flowing downwardly through the return tubing 54 enters the supply tubing 52 beneath the control valve 102 by way of the passage 164, whereby the control valve 102 is circulated to the surface.

In addition to running the pump 46 and the control valve 102 in and out independently in the foregoing manner, they may also be run in an out simultaneously if desired. Also, the control valve 102 may be run in and out on a wire line if desired.

The selector valves 104 and 106 are intended to be run in and out by means of wire lines in the particular construction illustrated.

General operation of control valves 102 and 130 by programming means 140 When the fluid operated pump 46 and the fluid operated control valve 102 are in their operating positions in the tubing system 34, and the control valve means 160 is set to connect the supply, return and production lines 142, 144 and 150 to the supply, return and production tubings 52, 54 and 40, respectively, the fluid operated control valves 102 and 130 are actuated by varying the operating fluid pressure in the supply line 142 and the supply tubing 52. Preferably, such varying of the operating fluid pressure in the supply line 142 and the supply tubing 52 involves utilizing the programming means 140 to shut off the flow of operating fluid under pressure, whereby the fluid pressures at the control valves 102 and 130 are either the maximum values existing when the operating fluid under pressure is flowing to the fluid operated pump 46, or the minimum, static values existing when the flow of operating fluid is shut oil by the programming means 140. As will be explained in more detail hereinafter, each time the programming means 140 reduces the fluid pressures at the control valves 102 and 130 from the maximum values to the minimum values and restores them to the maximum values, the control valves 102 and 130 actuate the selector valves 104, 106, 132, 134, 136 and 138 as required to switch production from one of the zones 26 and 28 to the other and to correspondingly switch the routing of the oil and gas from one set of oil and gas handling facilites 122 and 126, or 124 and 128, to the other,

The programming means 140 may operate on any desired time cycle, depending upon such factors as the relative productive capacities of the two zones 26 and 28, the relative demands for oil and gas from these zones, production quotas (if any) for these zones, and the like. Each of the zones 26 and 28 may be produced, before switching to the other, for a time interval ranging from minutes to days, depending upon circumstances. In its simplest form, the programming means 140 may consist merely of a three-way valve, not shown, which connects the supply line 142 either to the supply tubing 52, or to the return line 144 through a bypass line 175, and which is operated by a suitably-programmed timer, not shown. The programming means 140 operates the control valve 102 through the supply tubing 52, and operates the control valve through a line 176 leading from the programmeans to this control valve.

Control valve 102 Referring particularly to FIG. 9 of the drawings, the control valve 102 includes a valve body 180 having a tapered lower end 182 which is engaged with a tapered seat 184 when the control valve 102 is in its operating position. There is an annular clearance 186 around the valve body 180 above the passage 166. Operating fluid under pressure for actuating the pump 46 flows through the annular clearance 186 and the passage 166 to the pump.

Within the valve body 180 adjacent its upper end is a piston 188 vertically :reciprocable in a cylinder 190 and biased upwardly by a compression spring 192. The upper end of the piston 188 is exposed to the fluid pressure in the supply tubing 52 through a port 194 in the upper end of the valve body 180. The lower end of the piston 188 is exposed to the fluid pressure in the return tubing 54 through the passage 164, a chamber 196 below the seat 1 84 for control valve 102, a passage 198 in the lower end 182 of the valve body 180, clearances 200, 202 and 204, a port 206, a clearance 208 and a chamber 210 in which the spring 192 is disposed.

With this construction, when the programming means shuts off the flow of operating fluid to the supply tubing 52, the pressures acting on the upper and lower ends of the piston 188 are substantially equalized, both being equal to the static pressures due to the 'heads of fluid in the supply and return tubings 52 and 54. Under such conditions, the spring 192 displaces the piston 188 to the upper limit of its stroke. Conversely, when the programming means 140 permits the flow of operating fluid under pressure into the supply tubing 52, the fluid pressure acting on the upper end of the piston 188 overcomes the spring 192 and displaces the piston into its lowermost position, shown in FIG. 9 of the drawings.

The piston 188 includes an element 211 which is provided with straight, longitudinal, external splines 212 engaging complementary splines 214 on the valve body to prevent rotation of the piston as it moves upwardly and downwardly. The element 211 is provided internally thereof with helical longitudinal splines 216 meshed with complementary splines 218 on an actuator 220 oscillatable about the vertical axis of the valve body 180. For the particular two-zone completion 20 under consideration, the angle of the splines 216 and 218 and the stroke of the piston 188 are so related as to rotate the actuator 220 through an angle of 180 during each stroke of the piston, the actuator being moved through this angle in one direction during the upward stroke of the piston and *being moved through the same angle in the opposite direction during the downward stroke thereof. For a threezone completion, the angle through which the actuator 220 moves must be 120, for a four-zone completion it must be 90, and so forth.

Fixed to the lower end of the rotary actuator 220 is a rachet member 222 having two jaws spaced 180 apart for the two-zone completion 20 under consideration. (For a three-zone completion, the rachet member 222 requires three jaws spaced 120 apart, for a four-zone completion it requires four jaws spaced 90 apart, and so forth, the same being true of the other rachet members to be described hereinafter.) The rachet member 222 cooperates with a complementary rachet member 224 which is connected to a rotary control valve element 226 by straight, vertical splines. A compression spring 228 'biases the rachet member 224 upwardly into engagement with the rachet member 222. Also connected to the control valve element 226 by straight, vertical splines is a rachet mem- 7 her 230 having two jaws spaced apart by 180 and in phase with the jaws of the rachet member 224. The spring 228 biases the rachet member 230 downwardly into engagement with a complementary rac'het member 232 fixed to the valve body 180.

With the foregoing construction, each time the piston 188 moves upwardly, the ra'chet member 222 rotates relative to the rachet member 224 through an angle of 180, while the rachet members 230 and 232 cooperate to prevent rotation of the control valve element 226. During the subsequent downward stroke of the piston 188, the rachet members 222 and 224 cooperate to advance the control valve element 226 through an angle of 180, while the rachet member 230 rotates through the same angle relative to the rachet member 232. Thus, each time the programming means 140 reduces the pressure in the supply tubing 52 from its maximum value to its minimum value and restores it to its maximum value again, the control valve element 226 is advanced one angular step of 180. (This angular step will be 120 in the case of a three-zonecompletion, 90 in the case of a four-zone completion, and so forth.)

The control valve element 226 is provided adjacent its lower end with an axial passage 236 which communicates.

with the supply tubing 52, in both operating positions of the control valve element, through a radial port 238 in the valve body 180 and diametrically opposed radial ports 240 in the control valve element itself.

The control valve element 226 is provided, below the radial ports 240 therein, with radial ports 242 and 244 which are vertically spaced apart and which are angularly spaced apart 'by 180. When the control valve element 226 is in one of its operating positions, the radial port 242 communicates with a radial port 246 in the valve body 180. Similarly, when the control valve element 226 is in its other operating position, the radial port 244 therein communicates with a radial port 248. in the valve body 180. The ports 246 and 248 respectively communicate, through ports 250 and 252 and annular channels 254 and 256, with control passages 258 and 260 respectively leading to the lower-zone and upper-zone selector valves 106 and 104. External annular seals 262 on the valve body 180 isolate the two sets of ports mentioned from each other and from their environment.

With the foregoing construction, the pressure in the supply tubing 52 is delivered to the upper-zone selector valve 104 through the control passage 260 in one operating position of the control valve element 226, and is delivered to the lower-zone selector valve 106 through the control passage 258 in the other operating position of the control valve element. Thus, the supply-tubing pressure is delivered to the upper-zone and lower-zone selector valves 104 and 106 sequentially as the control valve element 226 is rotated step-by-step in the manner hereinbefore indicated. When the pressure in the supply tubing 52 is at its normal, operating value, it opens the particular selector valve 104 or 106 to which it is directed by the control valve 102. Since this pressure is directed to the control valves 104 and 106 sequentially, it opens them sequentially to produce the upper and lower zones 26 and 28 sequentially, one zone being produced in one operating position of the control valve element 226 and the other zone being produced in the other operating position of the control valve element. As hereinbefore discussed, the control valve element 226 is advanced step-by-step to accomplish this merely by varying the supply-tubing pressure between its maximum and minimum values under the control of the programming means 140.

The upper-zone and lower-zone selector valves 104 and 106 are identical, and operate identically, so that only the lower-zone selector valve 106 wil be considered in detail.

Lower-zone selector valve 106 Referring to FlG. 11 of the drawings, the selector valve 106 includes a valve body 268 engageable with a seat 270 therefor and inserted into a chamber 272. A bypass passage 274 equalizes the pressures above and below the selector valve 106 to permit its insertion into the chamber 272 by the action of gravity when it is installed by means of a wire line. For the purpose of wire-line installation and removal, the valve body 268 is provided at its upper end with a tapered head 278 engageable by a suitable fishing tool.

The valve body 268 is provided therethrough with a passage, designated generally by the numeral 280, having an upper end 282 in communication with the lower-zone inlet tubing 38 and having a lower end 284 in communication with a port 286 in register with the passage 110 leading to the lower end of the standing valve assembly 50. Encircling the passage 280 intermediate its upper and lower ends are opposed, upper and lower seats 290 and 292 for a ball valve 294. Normally, the ball valve 294 engages the lower seat 292, under the influence of gravity and the fluid pressure in the inlet tubing 38, to close the passage 280, thereby preventing flow of oil from the inlet tubing 38 to the standing valve assembly 50. In the event that the upper-zone selector valve 104 connects the upper Zone 26 to the standing valve assembly 50, and in the event that the fluid pressure in the upper-zone inlet tubing 36 is higher than that in the lower-zone inlet tubing 38, the ball valve 294 engages its upper seat 290 to prevent flow from the formation 26 into the formation 28. When the control valve 102 directs that production be from the lower zone 28, the ball valve 294 is held in an intermediate position, in a manner which will now be described, to permit downward flow through the passage 280.

The valve body 268 provides an axial cylinder 296 for an axially movable plunger 298 guided by upper and lower axial stems 300 and 302. The upper stern 300 is engageable with the ball valve 294 to lift it off its lower seat 292 and to hold it in a position intermediate such lower seat and the upper seat 290. Upward movement of the stem 300 beyond a position corresponding to the desired intermediate position for the ball valve 294 is prevented by engagement of an annular shoulder 304 on this stem with a seat 306 on the valve body 268.

The plunger 298, and the stems 300 and 302, are biased downwardly, into the positions shown in FIG. 11, by a compression spring 308. The upper end of the plunger 298 is.exposed to the static head of fluid in the return tubing 54 through radial ports 310 and an annular channel 312 in the valve body 268 and through a passage 314 in communication with the return tubing. (A similar passage 316 connects the return tubing 54 to the upper-zone selector valve 104.) An equal area of the lower end of the plunger 298 is exposed to the fluid pressure in the control passage 258 through radial ports 318 and an annular channel 320 in the valve body 268. The various sets of ports and channels mentioned are isolated from each other and their environment by external annular seals 321 on the valve body 268.

With the foregoing construction, when the control valve 102 connects the supply tubing 52 to the selector valve 106 through the control passage 258, and the programming means restores the supply tubing pressure to its maximum or normal, operating value, such pressure acts on the lower end of the plunger 298 to overcome the spring 308 and to cause the stem 300 to displace the ball valve 294 upwardly into an intermediate position between the upper and lower seats 290 and 292. Thus, the passage 280 through the selector valve 106 is opened to establish communication between the inlet tubing 38 and the inlet end of the standing valve assembly 50. Under such conditions, the pump 46 pumps oil from the lower zone 28, such oil being relatively gas free as the result of the gasoil separating action of the lower-zone U-tube 44. This is described fully in the aforementioned Patent No.

13 3,172,469, so that a further description herein is not required.

Upon actuation of the control valve 102 to switch production from the lower zone 28 to the upper zone 26, the pressure below the plunger 298 is reduced to that of the static head of fluid thereabove. Consequently, the spring 308 returns the plunger 298 and the stern 300 to the positions shown in FIG. 11, whereupon the ball valve 294 re-engages the lower seat 292 to close the passage 280. Under such conditions, communication between the lower zone 28 and the fluid operated pump 46 is cut oil.

The structure and operation of the upper-zone selector valve 104 are identical to those of the selector valve 106 so that a further description is not necessary.

Control valve 130 The control valve 130 of the zone selector means 120 at the surface 24 preferably is identical to and operates in the same manner as the bottom-hole control valve 102. More particularly, the programming means 140 causes the control valve 130 to sequentially connect control passages 322 and 324 to the supply line 142, in phase with the connection of the control passages 258 and 260 to the supply tubing 52 by the control valve 102. In view of the identity of structure and operation between the control valve 130 and the control valve 102, no further description of the control valve 130 is required.

The control passage 322 is connected to the lower-zone oil selector valve 134 and gas selector valve 138 corresponding to the bottom-hole lower-zone selector valve 106, while the control passage 324 is connected to the upperzone oil selector valve 132 and gas selector valve 136 corresponding to the bottom-hole upper-zone selector valve 104. This results in opening of the upper-zone selector valves 132 and 136 in phase with the bottom-hole upper-zone selector valve 104, and results in opening of the lower-zone selector valves 134 and 138 in phase with the bottom-hole lower-zone selector valve 106 (except for a time delay imposed on the valves 132 and 134, as discussed in the next paragraph).

As shown in FIG. 1 of the drawings, time delay means or devices 326 and 328 are inserted in the control passages 322 and 324, respectively, ahead of the lower-zone and upper-zone oil selector valves 134 and 132, respectively, and downstream from the corresponding lower-zone and upper-zone gas selector valves 138 and 136, respectively. The time delay devices 326 and 328 are responsive to the pressure signals in the control passages 322 and 324, respectively, and serve to delay actuation of the oil selector valves 134 and 132, respectively, for a length of time sufiicient to purge the production tubing 40 and the production line 150 of oil from the previously-produced formation 26 or 28, before connecting the line 150 to the oil handling equipment 122 or 124 corresponding to the zone to be produced next. This reduces intermingling of oil from the two zones to an absolute minimum when switching from one to the other, which is an important feature. The time delay devices 326 and 328 are located downstream from the gas selector valves 138 and 136 so as to insure that the gas selector valve corresponding to the zone being pumped at any instant is open, thereby preventing downward flow of gas from the zone being produced to the pump 46.

The selector valves 132, 134, 136 and 138 are all identical so that only the selector valve 132 will be considered in detail.

Selector valve 132 Referring to FIG. 12 of the drawings, the selector valve 132 includes a valve body 330 inserted into the branch line 146 leading from the common production fluid line 150 to the oil handling equipment 122. The valve body 330 is provided therethrough with a passage 332 for the upper-zone oil, such passagebeing encircled by an upstream-facing, annular valve seat 334. Engageable with the valve seat 334 is the head of a poppet valve 336 which is biased against the valve seat by the pressure of the incoming fluid. The stem of the poppet valve 336 carries a plunger 338 reciprocable in a cylinder 340, the valve being biased toward its seat by a compression spring 342 in engagement with the plunger.

The lower side of the plunger 338 is exposed to atmospheric pressure through a vent 344, while the upper side of the plunger is exposed to the control pressure in the passage 324 leading from the control valve 130. Consequently, when the programming means 140 directs the control valve to connect the control passage 324 to the supply line 142, and restores the normal, operating pressure in the supply line downstream from the programming means, such pressure is applied to the upper side of the plunger 338. This pressure then overcomes the spring 342- and unseats the valve 336, thereby permitting oil production from the upper zone 26 to flow through the upper-zone oil selector valve 132 into the upper-zone oil handling equipment 122. When the programming means directs the control valve 130 to reduce the pressure in the control passage 324 to its minimum value, which may be zero, the spring 342 closes the upper-zone oil selector valve 132.

The lower-zone oil selector valve 134, the upper-zone gas selector valve 136 and the lower-zone gas selector valve 138 operate in the same manner as the upper-zone oil selector valve 132. Consequently, a further description is not necessary.

Summary of operation The operation of the various components of the well completion 20 will be clear from the preceding description. Consequently, the over-all operation thereof will be summarized only briefly in this section, and only from the standpoint of switching production between the upper and lower zones 26 and 28.

The programming means 140 causes the control valves 102 and 130 to open first the upper-zone selector valves 104, 132 and 136 to produce the upper zone 26, and then the lower-zone selector valves 106, 134 and 138 to produce the lower zone 28. The selector valves 132 and 136 are opened in phase with the selector valve 104 and the selector valves 134 and 138 are opened in phase with the selector valve 106, except for the time delay provided by the time delay devices 326 and 328. Thus, the oil and gas produced by each formation are kept separate from the oil and gas produced by the other, which is an important feature. Also, excellent separation of the gas and oil produced by the respective zones 26 and 28 occurs in the respective U-tubes 42 and 44, which is another important feature.

Although exemplary embodiments of the invention have been disclosed herein for purposes of illustration, it will be understood that various changes, modifications and substitutions may be incorporated in such embodiments without departing from the spirit of the invention as defined by the claims which follow.

I claim:

1. A producing installation for a well drilled from the surface through an upper producing zone at least into a lower producing zone, including:

(a) a tubing system extending downwardly in the well at least into the lower producing zone;

(b) said tubing system including an upper-zone inlet tubing, a lower-zone inlet tubing and a production tubing;

(0) means providing fluid communication between the upper zone and said upper-zone inlet tubing at an upper level above the lower end of said tubing system;

(d) means providing fluid communication between the lower zone and said lower-zone inlet tubing at a lower level above the lower end of said tubing system;

(e) means interconnecting said inlet and production tubings at a bottom level adjacent the lower end of said tubing system and below said upper and lower levels, for conducting into said production tubing at said bottom level production fluid emanating from the upper zone and entering said upper-zone inlet tubing at said upper level, and for conducting into said production tubing at said bottom level production fluid emanating from the lower zone and entering said lower-zone inlet tubing at said lower level; and

(f) selector means for selectively placing said inlet tubings in fluid communication with said production tubing below said upper and lower levels.

2. A producing installation for an oil well drilled from the surface through an upper producing zone at least into a lower producing zone, including:

(a) a tubing system extending downwardly in the well at least into the lower producing zone;

(b) said tubing system including an upper-zone inlet tubing, a lower-zone inlet tubing and a production tubing in side-by-side relation;

(c) means providing fluid communication between the upper zone and said upper-zone inlet tubing at an upper level above the lower end of said tubing system;

((1) means providing fluid communication between the lower zone and said lower-zone inlet tubing at a lower level above the lower end of said tubing system;

(e) means inter-connecting said inlet and production tubings adjacent the lower end of said tubing system and below said upper and lower levels;

(f) upper-zone and lower-zone oil-handling facilities on the surface;

(g) upper-zone and lower-zone gas-handling facilities on the surface; and

(h), selector means for selectively placing said upperzone and lower-zone inlet tubings in fluid communication with said production tubing below said upper and lower levels, for correspondingly selectively plac ing said production tubing in fluid communication with said upper-zone and lower-zone oil-handling facilities at the surface, and for correspondingly selectively placing said upper-zone and lower-zone inlet tubings in fluid communication with said upper zone and lower-zone gas-handling facilities at the surface.

3. A producing installation for a well drilled from the surface through an upper producing zone at least into a lower producing zone, including:

(a) a tubing system extending downwardly in the well at least into the lower producing zone;

(b) said tubing system including an upper-zone inlet tubing, a lower-zone inlet tubing and a production tubing in side-by-side relation;

(c) means providing fluid communication between the upper zone and said upper-zone inlet tubing at an upper level above the lower end of said tubing system;

((1) means providing fluid communication between the lower zone and said lower-zone inlet tubing at a lower level above the lower end of said tubing system;

(e) means interconnecting said inlet and production tubings adjacent the lower end of said tubing system and below said upper and lower levels; and

(f) selector means, including valve means in said tubing system and controllable from the surface, for selectively placing said inlet tubings in fluid communication with said production tubing below said upper and lower levels.

4. A producing installation for a well drilled from the surface through an upper producing zone at least into a lower producing zone, including:

(a) a tubing system extending downwardly in the well at least into the lower producing zone;

(b) said tubing system including an upper-zone inlet tubing, a lower-zone inlet tubing and a production tubing in side-by-side relation;

(-c) means providing fluid communication between the upper zone and said upper-zone inlet tubing at an upper level above the lower end of said tubing system;

(d) means providing fluid communication between the lower zone and said lower-zone inlet tubing at a lower level above the lower end of said tubing system;

(e) means interconnecting said inlet and production tubings adjacent the lower end of said tubing system and below said upper and lower levels;

(f) selector means, including valve means in said tubing system and controllable from the surface, for selectively placing said upper-zone and lower-zone inlet tubings in fluid communication with said production tubing below said upper and lower levels;

(g) said valve means including upper-zone and lowerzone selector valves for respectively connecting said upper-zone and lower-zone inlet tubings in fiuid communication with said production tubing; and

(h) said valve means including a control valve operable from the surface for selectively operating said selector valves.

5. A producing installation for a well drilled from the surface through an upper producing zone at least into a lower producing zone, including:

(a) a tubing system extending downwardly in the well at least into the lower producing zone;

(b) said tubing system including an upper-zone inlet tubing, a lower-zone inlet tubing and a production tubing in side-by-side relation;

(c) means providing fluid communication between the upper zone and said upper-zone inlet tubing at an upper level above the lower end of said tubing system,

((1) means providing fluid communication between the lower zone and said lower-zone inlet tubing at a lower level above the lower end of said tubing system;

(e) means interconnecting said inlet and production tubings adjacent the lower end of sad tubing system and below said upper and lower levels;

(f) selector means, including valve means in said tubing system and controllable from the surface, for selectively placing said upper-zone and lower-zone inlet tubing in fluid communication with said production tubing below said upper and lower levels;

(g) said valve means including upper-zone and lowerzone selector valves, respectively disposed in said up per-zone and lower-zone inlet tubings, for respectively connecting said upper-zone and lower-zone inlet tubings in fluid communication with said production tubing; and

(h) said valve means including a control valve operable from the surface for selectively operating said selector valves.

6. A producing installation for a well drilled from the surface through an upper producing zone at least into a lower producing zone, including:

(a) a tubing system extending downwardly in the well at least into the lower producing zone;

a (b) said tubing system including an upper-zone inlet tubing, a lower-zone inlet tubing and a production tubing in side-by-side relation;

(0) means providing fluid communication between the upper zone and said upper-zone inlet tubing at an upper level above the lower end of said tubing sys-- tem;

(d) means providing fluid communication between the lower zone and said lower-zone inlet tubing at a lower level above the lower end of said tubing systern;

(e) means interconnecting said inlet and production tubings adjacent the lower end of said tubing system and below said upper and lower levels;

(f) selector means, including valve means in said tubing system and controllable from the surface, for selectively placing said upper-zone and lower-zone inlet tubings in fluid communication with said production tubing below said upper and lower levels;

(g) a fluid operated pump in said production tubing for pumping fluid from either of said inlet tubings upwardly through said production tubing to the surface;

(h) said tubing system including a supply tubing for delivering operating fiuid under pressure to said P p;

(i) said valve means including upper-zone and lowerzone selector valves, respectively disposed in said upper-zone and lower-zone inlet tubings, for respectively connecting said upper-zone and lower-zone inlet tubings in fluid communication with said production tubing below said pump; and

(j) said valve means including a control valve in said supply tubing and operable from the surface for selectively operating said selector valves.

7. A producing installation for a well drilled from the surface through an upper producing zone at least into a lower producing zone, including:

(a) a tubing system extending downwardly in the well at least into the lower producing zone;

(b) said tubing system including an upper-zone inlet tubing, a lower-zone inlet tubing and a production tubing in sicle-by-side relation;

(c) means providing fluid communication between the upper zone and said upper-zone inlet tubing at an upper level above the lower end of said tubing system;

(d) means providing fluid communication between the lower zone and saidlower-zone inlet tubing at a lower level above the lower end of said tubing system;

(e) means interconnecting said inlet and production tubings adjacent the lower end of said tubing system and below said upper and lower levels;

(f) selector means, including valve means in said tubing system and controllable from the surface, for

selectively placing said upper-zone and lower-zone inlet tubings in fluid communication with said production tubing below said upper and lower levels;

(g) a fluid operated pump in said production tubing for pumping fluid from either of said inlet tubings upwardly through said production tubing to the surface;

(h) said tubing system including a supply tubing for delivering operating fluid under pressure to said (i) said valve means including upper-zone and lowerz-one selector valves, respectively disposed in said upper-zone and lower-zone inlet tubings, for respectively connecting said upper-zone and lower-zone inlet tubings in fluid communication with said production tubing below said pump; and

(j) said valve means including a control valve in said supply tubing, and responsive to pressure variations in said supply tubing, for selectively operating said selector valves.

8. A producing installation for a'wel-l drilled from the surface through an upper producing zone at least into a lower producing zone, including:

(a) a tubing system extending downwardly in the well i at least into the lower producing zone;

I (b) said tubing system including an upper-zone inlet tubing, a lower-zone inlet tubing and a production tubing in side-by-side relation;

(c) means providing fluid communication between the upper zone and said upper-zone inlet tubing at an upper level above the lower end of said tubing system;

(d) means providing fluid communication between the lower zone and said lower-zone inlet tubing at a lower level above the lower end of said tubing system;

(e) means interconnecting said inlet and production tubings adjacent the lower end of said tubing system and below said upper and lower levels;

(f) selector means, including valve means in said tubing system and controllable from the surface, for selectively placing said upper-zone and lower-zone inlet tubings in fluid communication with said production tubing below said upper and lower levels;

(g) a fluid operated pump in said production tubing for pumping fluid from either of said inlet tubings upwardly through said production tubing to the surface;

(h) said tubing system including a supply tubing for delivering operating fluid under pressure to said pump;

(i) said valve means including upper-zone and lowerzone selector valves, respectively disposed in said upper-zone and lower-zone inlet tubings, for respectively connecting said upper-zone and lower-zone inlet tubings in fluid communication with said production tubing below said pump;

(j) said valve means including a control valve in said supply tubing, and responsive to pressure variations in said supply tubing, for selectively operating said selector valves; and

(k) means at the surface for varying the pressure in said supply tubing.

9. A producing installation for a well drilled from the surface through an upper producing zone at least into a lower producing zone, including:

' (d) means providing fluid communication between the lower zone and said lower-zone inlet tubing at a lower level above the lower end of said tubing system;

(e) means interconnecting said inlet and production tubings adjacent the lower end of said tubing system and below said upper and lower levels;

(f) selector means for selectively placing said inlet tubings in fluid communication with said production tubing below said upper and lower levels; and

(g) pump means in said tubing system for pumping fluid from either of said inlet tubings upwardly through said production tubing to the surface.

10. A producing installation for a well drilled-from the surface through an upper producing zone at least into a lower producing zone, including:

(a) a tubing system extending downwardly inthe well at least into the lower producing zone;

(b) said tubing system including an upper-zone inlet tubing, a lower-zone inlet tubing and a production tubing in side-by-side relation;

(c) means providing fluid communication between the upper zone and said upper-zone inlet tubing at an upper level above the lower end of said tubing system;

(d) means providing fluid communication between the lower zone and said lower-zone inlet tubing at a lower level above the lower end of said tubing system; I

(e) means interconnecting said inlet and production 19 tubings adjacent the lower end of said tubing system and below said upper and lower levels;

,(f) selector means for selectively placing said inlet tubings in fluid communication with said production tubing below said upper and lower levels;

(g) a fluid operated pump in said production tubing for pumping fluid from either of said inlet tubings upwardly through said production tubing to the surface; and

(h) said tubing system including a supply tub-ing for delivering operating fluid under pressure to said pump.

'11. A producing installation for a well drilled from the surface through an upper producing zone at least into a lower producing zone, including:

(a) a tubing system extending downwardly in the well at least into the lower producing zone;

(b) said tubing system including an upper-zone inlet tubing, a lower-zone inlet tubing and a production tubing in side-by-side relation;

(c) means providing fluid communication between the upper zone and said upper-zone inlet tubing at an upper level above the lower end of said tubing system;

(d) means providing fluid communication between the lower zone and said lower-zone inlet tubing at a lower level above the lower end of said tubing system;

, (e) means interconnecting said inlet and production tubings adjacent the lower end of said tubing system and below said upper and lower levels;

, (f) selector means in said tubing system for selectively placing said inlet tubings in fluid communication with said production tubing below said upper and lower levels;

(g) a fluid operated pump in said production tubing for pumping fluid from either of said inlet tubings upwardly through said production tubing to the surface;

(h) said tubing system including a supply tubing for delivering operating fluid under pressure to said pump;

(i) said selector means including a control valve in and responsive to pressure variations in said supply tubing for causing said selector means to selectively place said inlet tubings in fluid communication with W said production tubing; and

(j) means at the surface for varying the pressure in said supply tubing.

12. A producing installation for a well drilled from the surface through an upper producing zone at least into a lower producing zone, including:

(a) a tubing system extending downwardly in the well at least into the lower producing zone;

(b) said tubing system including an upper-zone inlet tubing, a lower-zone inlet tubing and a production tubing in side-by-side relation;

(c) means providing fluid communication between the upper zone and said upper-zone inlet tubing at an upper level above the lower end of said tubing system;

((1) means providing fluid communication between the lower zone and said lower-zone inlet tubing at a lower level above the lower end of said tubing system;

(e) means interconnecting said inlet and production I tubings adjacent the lower end of said tubing system and below said upper and lower levels;

(f) first selector means for selectively placing said upper-zone and lower-zone inlet tubings in fluid communication with said production tubing below said upper and lower levels;

(-g) a fluid operated pump in said production tubing for pumping fluid from either of said inlet tubings upwardly through said production tubing to the surface;

(h) said tubing system including a supply tubing for delivering operating fluid under pressure to said pump;

(i) upper-zone and lower-zone handling facilities at the surface;

(j) second selector means operable in phase with said first selector means for selectively placing said production tubing in fluid communication with said upper-zone and lower-zone handling facilities;

(k) said first and second selector means respectively including first and second control means responsive to pressure variations in said supply tubing; and

(1) means at the surface for varying the pressure in said supply tubing.

13. A producing installation for a well drilled from the surface through an upper producing zone at least into a lower producing zone, including:

(a) a tubing system extending downwardly in the well at least into the lower producing zone;

(b) said tubing system including an upper-zone inlet tubing, a lower-zone inlet tubing and a production tubing in side-by-side relation;

(c) means providing fluid communication between the upper zone and said upper-zone inlet tubing at an upper level above the lower end of said tubing system;

(d) means providing fluid communication between the lower zone and said lower-zone inlet tubing at .a lower level above the lower end of said tubing system;

(c) means interconnecting said inlet and production tubings adjacent the lower end of said tubing system and below said upper and lower levels;

(f) selector means for selectively placing said inlet tubings in fluid communication with said production tubing below said upper and lower levels;

(g) a fluid operated pump in said production tubing for pumping fluid from either of said inlet tubings up wardly through said production tubing to the surface;

(h) said tubing system including a supply tubing for delivering operating fluid under pressure to said pump; and

(i) said tubing system including a return tubing for returning to the surface spent operating fluid discharged by said pump.

14. A producing installation for a well drilled from the surface through an upper producing zone at least into a lower producing zone, including:

(a) a tubing system extending downwardly in the well at least into the lower producing zone;

(b) said tubing system including an upper-zone inlet tubing, a lower-zone inlet tubing and a production tubing in side-by-side relation;

(c) means providing fluid communication between the upper zone and said upper-zone inlet tubing at an upper level above the lower end of said tubing system;

((1) means providing fluid communication between the lower zone and said lower-zone inlet tubing at a lower level above the lower end of said tubing system;

(e) means interconnecting said inlet and production tubings adjacent the lower end of said tubing system and below said upper and lower levels;

(f) selector means for selectively placing said inlet tubings in fluid communication with said production tubing below said upper and lower levels;

(g) a standing valve assembly in said production tubing above the level at which said inlet tubings are connected in fluid communication with said production tubing by said selector means;

(h) a fluid operated pump, movable in said production tubing between the surface and an operating position wherein it is seated on said standing valve assembly, for pumping fluid from either of said inlet tubings upwardly through said production tubing to the surface; and i (i) said tubing system including a supply tubing for delivering operating fluid under pressure to said pump.

15. A producing installation for a well drilled from the surface through .an upper producing zone at least into a lower producing zone, including:

(a) a tubing system extending downwardly in the well at least into the lower producing zone;

(b) said tubing system including an upper-zone inlet tubing, a lower-zone inlet tubing and a production tubing in side-by-side relation;

(c) means providing fluid communication between the upper zone and said upper-zone inlet tubing at an upper level above the lower end of said tubing system;

(d) means providing fluid communication between the lower zone and said lower-zone inlet tubing at a lower level above the lower end of said tubing system;

(e) means interconnecting said inlet and production tubings adjacent the lower end of said tubing system and below said upper and lower levels;

(f) selector means, including valve means in said tubing system and controllable from the surface, for selectively. placing said inlet tubings in fluid communication with said production tubing below said upper and lower levels; and

(g) said selector means including means 'for preventing flow from either of said inlet tubings to the other.

References Cited UNITED STATES PATENTS 1,389,007 8/1921 Norbye 166105 2,293,196 8/1942 Crump 1666 2,593,497 4/1952 Spearow 16668 X 2,605,712 8/1952 Davis et al l0346 2,822,757 2/1958 Co berly l0346 2,852,079 9/1958 Hebard.

2,939,533 6/1960 Coberly 166-68 3,054,456 9/1962 Hammaker 166-102 X 3,064,580 11/1962 Calvert et al 16645 X 3,086,592 4/1963 Hoch 16667 X 3,115,187 12/1963 Brown.

3,172,469 3/ 1965 C'oberly et al 166-105 X CHARLES E. OCONNELL, Primary Examiner.

I. A. CALVERT, Assistant Examiner. 

1. A PRODUCING INSTALLATION FOR A WELL DRILLED FROM THE SURFACE THROUGH AN UPPER PRODUCING ZONE AT LEAST INTO A LOWER PRODUCING ZONE, INCLUDING: (A) A TUBING SYSTEM EXTENDING DOWNWARDLY IN THE WELL AT LEAST INTO THE LOWER PRODUCING ZONE; (B) SAID TUBING SYSTEM INCLUDING AN UPPER-ZONE INLET TUBING, A LOWER-ZONE INLET TUBING AND A PRODUCTION TUBING; (C) MEANS PROVIDING FLUID COMMUNICATION BETWEEN THE UPPER ZONE AND SAID UPPER-ZONE INLET TUBING AT AN UPPER LEVEL ABOVE THE LOWER END OF SAID TUBING SYSTEM; (D) MEANS PROVIDING FLUID COMMUNICATION BETWEEN THE LOWER ZONE AND SAID LOWER-ZONE INLET TUBING AT A LOWER LEVEL ABOVE THE LOWER END OF SAID TUBING SYSTEM; (E) MEANS INTERCONNECTING SAID INLET AND PRODUCTION TUBINGS AT A BOTTOM LEVEL ADJACENT THE LOWER END OF SAID TUBING SYSTEM AND BELOW SAID UPPER AND LOWER LEVELS, FOR CONDUCTING INTO SAID PRODUCTION TUBING AT SAID BOTTOM LEVEL PRODUCTION FLUID EMANATING FROM THE UPPER ZONE AND ENTERING SAID UPPER-ZONE INLET TUBING AT SAID UPPER LEVEL, AND FOR CONDUCTING INTO SAID PRODUCTION TUBING AT SAID BOTTOM LEVEL PRODUCTION FLUID EMANATING FROM THE LOWER ZONE AND ENTERING SAID LOWER-ZONE INLET TUBING AT SAID LOWER LEVEL; AND (F) SELECTOR MEANS FOR SELECTIVELY PLACING SAID INLET TUBINGS IN FLUID COMMUNICATION WITH SAID PRODUCTION TUBING BELOW SAID UPPER AND LOWER LEVELS. 